This invention relates to multi-stage reactors in which a liquid phase and a gas phase flow countercurrently, and in which solid phase particles move from one stage of the reactor to the next. The invention also relates to reactions involving liquid, gas and solid phases in which the solid may be a catalyst for the reaction, inert, or a reactant.
In many reactions, it is necessary to achieve intimate contact between a gaseous phase, a liquid phase and a solid. The gas or mixture of gases may be a reactant, may be required to maintain catalyst activity, may be necessary to maintain an atmosphere or environment suitable for the required operation, or may be required for agitation. The liquid or mixture of liquids may be a reactant, a solvent or a carrying agent. The solid or mixture of solids may be a catalyst, an absorbent, a reactant or a heat transfer agent.
Typically in the prior art the gas and liquid phase flow concurrently through a fixed bed or beds of the solid phase. Although less common, countercurrent flow of reactants is also well known, and there are some reactions involving moving solid phases, for example, moving beds of catalyst particles.